About
RGraph is a JavaScript charts library based on
HTML5 SVG and canvas. RGraph is mature (over 15 years
old) and has a wealth of features making it an ideal
choice to show charts on your website.
License
RGraph can be used for free under the GPL or if
that doesn't suit your situation there's an
inexpensive (£99) commercial license available.
Download
Get the latest version of RGraph (version 6.17) from
the download page. There's also older versions available,
minified files and links to cdnjs.com hosted libraries.
The putImageData function
The putImageData
function allows you to add an
ImageData
object that you have been manipulating back onto the
canvas
. You
pass the function the ImageData
object and the X/Y coordinates of where you
want it placed. Optionally you can specify
which portion of the ImageData
object to use.
Arguments to the function
- The
ImageData
object to copy onto thecanvas
- The
x-axis
coordinate to place it at (top left corner) - The
y-axis
coordinate to place it at (top left corner) - dirtyX Used to specify what portion of the
ImageData
object to use (Optional) - dirtyY Used to specify what portion of the
ImageData
object to use (Optional) - dirtyW Used to specify what portion of the
ImageData
object to use (Optional) - dirtyH Used to specify what portion of the
ImageData
object to use (Optional)
An example
<script>
window.onload = function ()
{
var canvas = document.getElementById('cvs');
var context = canvas.getContext('2d');
// Copies an ImageData object onto the canvas
context.putImageData(imgData);
}
</script>